These days, legendary 90’s supermodel Cindy Crawford laments not the inevitable loss of collagen or slowing metabolism that accompanies aging. She simply wants her old hair back. “Everyone loves to talk about plastic surgery and all that stuff, but hair is the most underestimated thing," she recently told Allure magazine."If you have good color and shiny hair, you can see that across a room. Now I look at my daughter's and I'm like, 'You have my old hair! I want it back!'"

That’s because just as our skin succumbs to the pull of gravity, our hair — an oft-overlooked feature in the gargantuan anti-aging industry — changes in ways that we wish it wouldn’t. Yup, we’re talking hair loss, thinning, graying and dullness.

While plenty of experts say the slump starts after age 30, it varies from person to person. “There are many factors that play a role," says Alan J. Bauman, M.D., a top U.S. medical expert on hair loss and restoration. "Heredity, diet habits and even over-styling can cause your hair to age prematurely. An often overlooked factor is smoking, which is especially damaging to your hair.”

Mindy Goldstein, Ph.D., former president of the Society of Cosmetic Chemists, echoes this sentiment. “The follicles in aging hair are smaller and have less pigment,” she explains. “So the thick, coarse hair of a young adult eventually becomes thin, fine, light-colored hair.”

Mane Matters

Gray hairs may be the most obvious sign of impending dotage, but they seem less distressing when we take a closer look at all the other annoying ways hair quality degrades with age. “The first sign of loss is shine and opulence, which we associate with healthy hair and youth,” says N.Y.C.-based hairstylist, author and salon owner Eva Scrivo. Another issue: thinning. According to the American Academy of Dermatology, about 30 million American women are dealing with hereditary hair loss. Diet, medical problems, hormones, stress and certain medications can also be factors, so if the loss is dramatic (more than typical 100 strands you should expect to shed every day), see a doctor to rule out any major issues.